The brain?s auditory system provides two crucial pieces of information about a sound in the environment: its identity and location. Patients who have suffered injury to the temporal or parietal lobes can present specific deficits in just one of these abilities, while the basic ability to hear remains intact. This dissociation suggests that the auditory cortex may process these aspects of sound along separate neural pathways that diverge beyond the stage of basic sensory analysis, a hypothesis supported by anatomical work in lower primates. How the physiological response properties of cells in different regions of auditory cortex of an alert monkey support anatomically inspired models of parallel processing is unknown. Though sensitivity to the spatial location of a sound has been demonstrated, sensitivity to the binaural cues thought to underlie sound localization is not well understood. Similarly, cells can be selective for a complex stimulus like a vocalization, but these cells have not been characterized with basic stimuli such as modulation of sound amplitude or frequency (common characteristics of animal calls and human language). Responses of single neurons in the auditory cortex of alert monkeys will be studied with a battery of stimuli designed to establish a physiological topography within the primary auditory cortex and between surrounding fields. Divergence of spatial and spectrotemporal sensitivities, or other functional differences between cortical fields, would unify the current anatomical model with functional theories of organization in auditory cortex.